That's a massive mess, so I've cleaned it up so we can all read it - note the use of [code] tags to maintain layout.
exfat is a proprietary format and in Linux is accessed via a userland tool called fuse - which is basically a translation layer before the I/O is passed to the kernel. If the tools are properly installed I wouldn't expect it to be really slow unless maybe you are doing really large transfers. Like I said, we need more detail about your specific situation.
The Mint I have doesn't have all those snap allocations - didn't know the latest Mint had gone that way. There have been quite a few reports of that slowing down the whole system for Ubuntu, on which Mint is based. Sorry can't help at the moment as I don't have such a system - perhaps someone else can.
Code:
$ lsblk -f -o +SIZE
NAME FSTYPE LABEL UUID MOUNTPOINT SIZE
sda 447.1G
├─sda1
│ vfat D49C-A307 /boot/efi 512M
└─sda2
LVM2_m n11HQp-q12B-REgH-4uhW-snRK-c27M-VvOcb0 446.6G
├─mint--vg-root
│ ext4 1868cf0c-0be2-41d2-9b01-6c4897fbc427 / 430.8G
└─mint--vg-swap_1
swap 82d967dd-7f64-4bcd-abea-bae08292c3f0 [SWAP] 15.9G
sdb 1.8T
├─sdb1
│ 128M
└─sdb2
ntfs Filestore D2D4E9F7D4E9DDAB /media/ajb 1.8T
sdc 3.7T
├─sdc1
│ vfat EFI 70D6-1701 200M
└─sdc2
exfat 53A4-08FA 3.7T
sdd 931.5G
└─sdd1
ntfs AJs reserve
4E1AEA7B1AEA6007 /media/ajb 931.5G
sde udf CDROM 558c337400000000 28.9G
└─sde1
vfat MOVIEZ 8BFE-D087 /media/ajb 28.9G
sr0 1024M
│ ext4 1868cf0c-0be2-41d2-9b01-6c4897fbc427 / 430.8G
└─mint--vg-swap_1
swap 82d967dd-7f64-4bcd-abea-bae08292c3f0 [SWAP] 15.9G
Lacie 4TB drive
